Apparatus and methods for repair of a cardiac valve

ABSTRACT

An annuloplasty ring for repairing a cardiac valve includes an expandable support member having oppositely disposed proximal and distal end portions and a main body portion between the end portions. The proximal end portion of the support member includes a plurality of wing members that extend from the main body portion. Each of the wing members includes at least one hook member for embedding into a cardiac wall and the valve annulus to secure the annuloplasty ring in the valve annulus. The annuloplasty ring may be expanded into full contact engagement with the annulus of the cardiac valve by an inflatable balloon. Methods for repairing a cardiac valve using the annuloplasty ring are also provided.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/850,508, filed on May 20, 2004, which claims priority from U.S.provisional patent application Ser. No. 60/472,030, filed on May 20,2003, and U.S. provisional patent application Ser. No. 60/547,416, filedon Feb. 26, 2004. The subject matter of the above-listed patentapplications is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to an apparatus and methods for repair ofa cardiac valve, and is particularly directed to an apparatus andmethods that include an annuloplasty ring for the correction of mitralvalve and tricuspid valve disorders.

BACKGROUND OF THE INVENTION

There are two atrio-ventricular valves in the heart; one on the leftside of the heart and one on the right side of the heart. The left sideatrio-ventricular valve is the mitral valve and the right sideatrio-ventricular valve is the tricuspid valve. Both of these valves aresubject to damage that requires that the valve be repaired or replaced.Experience has shown that damaged valves can be surgically repaired, andthat the long term results obtained from valve repair can be better thanreplacement of the valve.

The mitral and tricuspid valves differ significantly in anatomy. Whilethe annulus of the mitral valve is generally D-shaped, the annulus ofthe tricuspid valve is more circular. The effects of the valvulardysfunction vary between the mitral valve and the tricuspid valve.Mitral valve regurgitation has more severe physiological consequences tothe patient than does tricuspid valve regurgitation, a small amount ofwhich is tolerable. In patients with valvular insufficiency, it isincreasingly common surgical practice to retain the natural valves andto attempt to correct the defect. Many of these defects are associatedwith dilation of the valve annulus. This dilatation not only preventscompetence of the valve, but also results in distortion of the normalshape of the valve orifice. Remodeling the valve annulus is thereforecentral to most reconstructive procedures for both the mitral andtricuspid valves.

Mitral or tricuspid valve annuloplasty is a restoration of the valveannulus, which effects full closure of the valve's leaflets byreestablishing the size and the shape of the normal mitral or tricuspidvalve annulus. Surgical procedures such as annuloplasty more commonlyincorporate the use of a prosthetic ring, where the ring is implantedover or within the mitral or tricuspid valve annulus.

In mitral valve insufficiency, the valve leaflets do not fully close anda certain amount of blood leaks back into the left atrium when the leftventricle contracts. As a result, the heart has to work harder bypumping not only the regular volume of the blood, but also the extravolume of blood that regurgitated back into the left atrium. The addedworkload creates an undue strain on the left ventricle. This strain caneventually wear out of the heart and result in morbidity when theconditions are prolonged and severe enough. Consequently, properfunction of the mitral valve is critical to the pumping efficiency ofthe heart.

Many surgical procedures have been described to correct pathology of thevalve leaflets, chordal tendineae, and papillary muscles. In mitralvalve repair, it is desirable to preserve the normal distance betweenthe two fibrous trigones. The trigones more or less straddle theanterior leaflet portion of the mitral annulus. A significant surgicalreduction of the inter-trigonal distance could cause left ventricularoutflow tract obstruction. Thus, it is desirable to maintain the naturalinter-trigonal distance after mitral valve surgery. Consequently, when amitral valve is repaired, the result is generally a reduction in size ofthe posterior segment of the mitral valve annulus.

In a mitral valve repair, it is necessary to either diminish orconstrict the involved segment of the mitral annulus so that theleaflets may coapt correctly when closing or, alternatively, tostabilize the annulus to prevent the possibility of dilatation fromoccurring. The latter is frequently achieved by implantation of aprosthetic ring in the supra-annular position. The purpose of the ringis to restrict and/or support the annulus to correct and/or preventvalvular insufficiency. However, it is important not to over-restrictthe annulus or unacceptable valve stenosis could result.

As described above, in mitral valve repair, constriction of the mitralannulus should take place only in the area of the posterior portion ofthe native valve annulus. Shortening of the posterior portion of themitral valve annulus may be accomplished by implanting an inexpansiblerigid ring. With this approach, the surgeon must accurately choose thesize of the ring that would prevent insufficiency, yet will not causesignificant valve stenosis. A second approach uses a contractible ringthat may be plicated during implantation. This approach has adisadvantage that a surgeon must accurately gauge not only the ring sizeto use, but also how to space the implanting sutures in the ring and thenative annulus so that, when implanted, insufficiency is minimized. Athird approach involves semi-expandable rings that may be contractedonly in appropriate segments of the native annulus (but not in theanterior portion). The natural inter-trigonal distance should bemaintained and the anterior leaflet should not be diminished in thiscircumstance.

In tricuspid valve repair, constriction of the annulus usually takesplace in the posterior leaflet segment and in a small portion of theadjacent anterior leaflet. The septal leaflet segment is not usuallyrequired to be shortened.

Mitral and tricuspid valve disease is traditionally treated by surgicalrepair with an annuloplasty ring or surgical or replacement with a valveprosthesis. However, surgical valve replacement or repair is often anexacting operation that is done through a surgical technique where thethoracic cavity is opened. The operation requires use of a heart-lungmachine for external circulation of the blood as the heart is stoppedand opened during the surgical intervention and the artificial cardiacvalves and/or annuloplasty rings are sewed in under direct vision. Thisoperation exposes the patient to many risks especially in the elderlypopulation. A percutaneous procedure that can be performed under localanesthesia in the cardiac catherization lab, rather than in cardiacsurgery, could therefore offer tremendous benefits for these patients,many of whom have no options today. A minimally invasive surgicaltechnique and percutaneous approach for delivering a prosthetic ring formitral or tricuspid valve repair could be one of the most prominenttools in order to provide opportunities to treat patients with severevalvular insufficiency and/or end stage heart failure.

SUMMARY OF THE INVENTION

The present invention is an annuloplasty ring for repairing a cardiacvalve. The annuloplasty ring comprises an expandable support memberhaving oppositely disposed proximal and distal end portions and a mainbody portion between the end portions. The proximal end portion of thesupport member comprises a plurality of wing members that extend fromthe main body portion. Each of the wing members includes at least onehook member for embedding into a cardiac wall and into the annulus ofthe cardiac valve to secure the annuloplasty ring in the annulus.

In accordance with one aspect of the invention, the hook members, whenembedded into the cardiac wall and the valve annulus, extend distallyfrom the wing members.

In accordance with another aspect of the invention, the main bodyportion has a concave cross-sectional shape for conforming to the convexshape of the valve annulus.

In accordance with another aspect of the invention, each of the wingmembers has a concave cross-sectional shape for conforming to the convexshape of the valve annulus.

In accordance with another aspect of the invention, the main bodyportion and the wing members are resiliently bendable from the concavecross-sectional shapes into flatter cross-sectional shapes for deliveryand placement of the annuloplasty ring.

In accordance with another aspect of the invention, the apparatusfurther comprises a constraining wire for temporarily holding the wingmembers in the flatter cross-sectional shape. The hook members extendgenerally radially when the wing members are being held in the flattercross-sectional shape by the constraining wire.

In accordance with another aspect of the invention, the hook members areresiliently bendable to extend proximally inside a delivery capsule orsleeve during delivery of the annuloplasty ring into the valve annulus.

In accordance with another aspect of the invention, the annuloplastyring further comprises a layer of biocompatible material covering atleast a portion of the distal end portion and the main body portion ofthe support member.

In accordance with another aspect of the invention, the support memberis made from a shape memory material that is responsive to changes intemperature above and below a predetermined temperature transitionrange. The support member has a first configuration when the temperatureis below the predetermined temperature transition range and a secondconfiguration when heated above the predetermined temperature transitionrange.

In accordance with another aspect of the invention, the annuloplastyring is insertable into the annulus of the cardiac valve in the firstconfiguration and is thereafter heatable above the predeterminedtemperature transition range to change the support member into thesecond configuration, wherein movement of the support member into thesecond configuration causes a reduction in size of the opening definedby the valve annulus.

In accordance with another aspect of the invention, the support memberis expandable by an inflatable balloon so that the annuloplasty ringengages the annulus of the cardiac valve.

The present invention further includes an apparatus for repairing acardiac valve. The annuloplasty ring comprises an expandable supportmember having oppositely disposed proximal and distal end portions and amain body portion between the two end portions. The proximal end of thesupport member includes a plurality of wing members that extend from themain body portion. Each of the wing members includes at least one hookmember for embedding into a cardiac wall and the annulus of the cardiacvalve to secure the annuloplasty ring in the annulus. An inflatableballoon expands the support member so that the annuloplasty ring engagesthe annulus of the cardiac valve with full contact.

In accordance with one aspect of the invention, the balloon has anhourglass shape defined by first and second bulb sections connected by acenter section having a smaller diameter than the bulb sections. Theannuloplasty ring is positioned about the center section.

The present invention further provides a method for repairing a cardiacvalve. According to the inventive method, an annuloplasty ring having anexpandable support member is provided. The annuloplasty ring is placedaround an inflatable balloon in a secured manner. The balloon andannuloplasty ring are then inserted into an atrial chamber and advanceduntil the annuloplasty ring is positioned within the annulus of thecardiac valve to be repaired. Next, the support member is extended withthe balloon so that the annuloplasty ring engages the annulus of thecardiac valve. The annuloplasty ring is secured in the valve annulus.The balloon is then collapsed and removed from the atrial chamber.

In accordance with another aspect of the inventive method, the balloonhas an hourglass shape defined by first and second bulb sectionsconnected by a center section having a smaller diameter than the bulbsections. The annuloplasty ring is positioned about the center section.

In accordance with another aspect of the inventive method, a first bulbsection of the balloon is positioned within the leaflets of the nativevalve so that, when the balloon is inflated, the first bulb pushes thevalve leaflets back to protect the leaflets during expansion of thesupport member.

In accordance with another aspect of the inventive method, the supportmember has oppositely disposed proximal and distal end portionsconnected by a main body portion that has a concave cross-sectionalshape. The step of expanding the support member with the balloon so thatthe annuloplasty ring engages the annulus of the cardiac valve includesconforming the concave main body portion to the convex shape of thevalve annulus to help locate and secure the annuloplasty ring in thevalve annulus.

In accordance with another aspect of the inventive method, the proximalend of the support member comprises a plurality of wing members thatextend from the main body portion. Each of the wing members includes atleast one resiliently bendable hook member extending from each of thewing members. The method further includes the step of embedding the hookmembers into a cardiac wall to further secure the annuloplasty ring inthe valve annulus.

In accordance with another aspect of the inventive method, each of thewing members has a concave cross-sectional shape for conforming to theconvex shape of the valve annulus. The method further comprises the stepof pulling the wing members into a flatter cross-sectional shape with aconstraining wire for placement of the annuloplasty ring. The hookmembers extend generally radially when the wing members are being heldby the constraining wire.

In accordance with another aspect of the inventive method, the hookmembers are bent to extend proximally inside a delivery capsule orsleeve for delivery of the annuloplasty ring.

In accordance with another aspect of the inventive method, theconstraining wire is released after the step of expanding the supportmember with the balloon so that the wing members bend radially outwardto position the hook members above the valve annulus for embedding intothe valve annulus.

In accordance with another aspect of the inventive method, the step ofreleasing the constraining wire causes the hook members to embed intothe cardiac wall in the distal direction.

In accordance with another aspect of the inventive method, the supportmember is made from a shape memory material that is responsive tochanges in temperature above and below a predetermined temperaturetransition range. The support member has a first configuration when thetemperature is below the predetermined temperature transition range anda second configuration when heated above the predetermined temperaturetransition range. The method further includes cooling the support memberprior to inserting the annuloplasty ring into the annulus of the cardiacvalve in order to place the support in the first configuration.

In accordance with another aspect of the inventive method, the supportmember is heated above the predetermined temperature transition range sothat the support member changes into the second configuration.

In accordance with another aspect of the inventive method, heating thesupport member is done following the expansion of the support memberwith the balloon. The heating process contracts the annuloplasty ringand thereby restricts the valve annulus to support the valve annulus andcorrect valvular insufficiency.

In accordance with another aspect of the inventive method, the step ofheating is accomplished by exposing the support member to bodytemperature.

In accordance with another aspect of the inventive method, the balloonand annuloplasty ring are inserted into the atrial chamberpercutaneously via an intravascular catheter.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features of the present invention will becomeapparent to those skilled in the art to which the present inventionrelates upon reading the following description with reference to theaccompanying drawings, in which:

FIG. 1 is a schematic perspective view of a heart implanted with anannuloplasty ring for repairing a cardiac valve in accordance with thepresent invention;

FIG. 2 is a schematic plan view of the heart and the annuloplasty ringshown in FIG. 1;

FIG. 3 is a perspective view of the annuloplasty ring of FIG. 1illustrating the ring in a fully deployed condition;

FIG. 4 is a perspective view similar to FIG. 3 illustrating analternative construction for the annuloplasty ring;

FIG. 5 is a perspective view of the annuloplasty ring of FIG. 3 with thering being shown in a radially collapsed condition for delivery (priorto expansion by a balloon);

FIG. 6 is a side view, partly in section, of an apparatus for repairinga cardiac valve comprising the annuloplasty ring of FIG. 3, theapparatus being shown at an initial stage of delivery into an atrialchamber;

FIG. 7 is a side view similar to FIG. 6 illustrating the apparatus at asubsequent stage of delivery;

FIG. 8 is a side view similar to FIG. 7 illustrating the apparatus atanother subsequent stage of delivery;

FIG. 9 is a side view similar to FIG. 8 illustrating the annuloplastyring being deployed in the valve annulus by expansion of a balloon;

FIG. 10 is an enlarged view of a portion of FIG. 9;

FIG. 11 is a side view similar to FIG. 9 illustrating a further step inthe deployment of the annuloplasty ring;

FIG. 12 is an enlarged view of a portion of FIG. 11;

FIG. 13 is a side view similar to FIG. 11 illustrating the annuloplastyring implanted in the valve annulus with the balloon deflated; and

FIG. 14 is a side view similar to FIG. 13 illustrating the constrictingeffect that the shape memory material of the annuloplasty ring has onthe valve annulus.

DETAILED DESCRIPTION OF EMBODIMENTS

The present invention relates to an apparatus and methods for repair ofa cardiac valve. As representative of the present invention, FIG. 1illustrates an apparatus 10 that includes an annuloplasty ring 12 forrepairing a dysfunctional cardiac valve, such as a mitral valve 14. Itshould be understood, however, that the apparatus 10 disclosed hereincould be used to repair not only a mitral valve, but also other cardiacvalves and, in particular, a tricuspid valve.

The mitral valve 14 is located between the left atrium and the leftventricle and functions to prevent the backflow of blood from the leftventricle into the left atrium during contraction. As best seen in FIG.2, the mitral valve 14 has a D-shaped annulus 15 that defines theopening between the left atrium and the left ventricle. The mitral valve14 is formed by two leaflets; namely, the anterior leaflet 16 and theposterior leaflet 18. The anterior leaflet 16 extends along thegenerally planar base of the D-shaped valve annulus 15 between twofibrous trigones (not shown). It is desirable to maintain the distance X(FIG. 2) between the two trigones after the valve repair procedure iscompleted. The posterior leaflet 18 extends arcuately around the curvedportion of the D-shaped annulus 15 of the mitral valve 14. Chordaetendineae 20 (FIG. 1) extend between the free edges 22 of both leaflets16 and 18 to the papillary muscles 24 in the left ventricle.

The annuloplasty ring 12 for repairing the dysfunctional mitral valve 14comprises an expandable support member 30 that resembles a completestent. The annuloplasty ring 12 described herein has an annularconfiguration that mimics the D-shape of the native annulus 15, but itwill be understood by those skilled in the art that the annuloplastyring could be a partial ring and thus have a C-shape, a U-shape, oranother suitable configuration. The support member 30 is both flexibleand resilient, and, as discussed in more detail below, is made of ashape memory material such as Nitinol. Other suitable medical grademetals or plastics having shape memory characteristics can also be usedfor the support member 30. The flexible and expandable properties of thesupport member 30 allow it to conform to the three-dimensional shape ofthe native valve annulus 14.

The support member 30 comprises a continuous series of W-shapedsegments, although it is contemplated that other geometries could beused. The lower, as viewed in FIG. 3, tips of the W-shaped segments forma distal end portion 32 of the support member 30 and the elongated uppertips of the W-shaped segments form a proximal end portion 34 of thesupport member. For purposes of this disclosure, the term “proximal”means on the inflow or upstream side of the annuloplasty ring 12 and“distal” means on the outflow or downstream side of the annuloplastyring. Thus, the distal end portion 32 of the support member 30 is theleading edge of the support member when the annuloplasty ring 12 isinserted into the body. Further, as illustrated in FIG. 6, the letter Aindicates the distal direction and the letter B indicates the proximaldirection.

Referring again to FIG. 3, a main body portion 36 of the support member30 is defined between the distal and proximal end portions 32 and 34.The main body portion 36 has a concave cross-sectional shape forconforming to the convex shape of the valve annulus 15. It iscontemplated that the pattern of the support member 30 and/or thethickness of the support member in the main body portion 36 may bealtered along the inter-trigonal distance X in order to maintain thisdistance and ensure more retraction along the posterior leaflet 18.

The proximal end portion 34 of the support member 30 comprises aplurality of wing members 40 that resemble arches and which extendintegrally from the main body portion 36 generally in the proximaldirection B. The wing members 40 also have a concave cross-sectionalshape for conforming to the convex shape of the valve annulus 15. As isshown in FIGS. 5-10, the main body portion 36 and the wing members 40are resiliently bendable from their concave cross-sectional shapes intoflatter cross-sectional shapes for delivery and placement of theannuloplasty ring 12.

Each wing member 40 of the support member 30 has a tip portion 42 (FIG.3) that includes an aperture 44 for receiving a wire. Further, the tipportion 42 of each wing member 40 includes at least one hook member 46for embedding into a cardiac wall to secure the annuloplasty ring 12 inthe annulus 15 of the mitral valve 14. The hook members 46 projectoutward from the wing members 40 and have sharp pointed ends. It iscontemplated that the pointed ends of the hook members 46 could includeone or more barbs (not shown), similar to the barbs used in fishinghooks, to prevent pull-out of the hook members once they are embedded inthe valve annulus 15.

As mentioned above, the support member 30 is made from a shape memorymaterial, such as Nitinol, that is responsive to changes in temperatureabove and below a predetermined temperature transition range of 75-95degrees Fahrenheit, although it should be understood that othertemperature transition ranges could be used. The support member 30 has afirst configuration when its temperature is below the predeterminedtemperature transition range and a second configuration when heatedabove the predetermined temperature transition range. In accordance withone aspect of the invention, the annuloplasty ring 12 is inserted intothe annulus 15 of the mitral valve 14 in the first configuration, whichis an expanded condition, and is thereafter heated above thepredetermined temperature transition range to change the support member30 into the second configuration, which is a contracted condition thatis the desired pre-shape memorized by the material.

FIG. 4 illustrates the annuloplasty ring 12 with a layer 50 ofbiocompatible material covering sections of the distal end portion 32and the main body portion 36 of the support member 30. The layer 50 ofbiocompatible material may be a synthetic such as Dacron®, woven velour,polyurethane, PTFE, or heparin-coated fabric. Alternatively, the layer50 may be a biological material such as bovine or equine pericardium, ahomograft, patient graft, or a cell-seeded tissue. The layer 50 cancover either the inside surface of the support member 30, the outsidesurface of the support member, or can be wrapped around both the insideand outside surfaces. The layer 50 may be attached around the entirecircumference of the support member 30 or, alternatively, may beattached in sections as shown in FIG. 4 to allow the support member tomore easily expand and contract.

The apparatus 10 further comprises a releasable constraining wire 52(FIG. 5) for temporarily holding the wing members 46 in the flattercross-sectional shape shown in FIGS. 5-10 during delivery and placementof the annuloplasty ring 12. The constraining wire 52 can be made from avariety of different materials including metals, polymers, synthetics,fabrics, and biological tissues. As illustrated in FIGS. 5 and 7-10, thehook members 46 extend generally radially when the wing members 40 arebeing held in the flatter cross-sectional shape by the constraining wire52. However, as shown in FIG. 6, the hook members 46 are resilientlybendable to extend proximally inside a delivery capsule 54 duringdelivery of the annuloplasty ring 12 into the valve annulus 15. Itshould be understood that the delivery capsule 54 could have a varietyof configurations, including a sleeve or sheath.

The apparatus 10 further comprises an inflatable balloon 60 (FIG. 6) forexpanding the annuloplasty ring 12 into full and complete contact withthe annulus 15 of the cardiac valve 14. The balloon 60 has an hourglassshape defined by first and second bulb sections 62 and 64 connected by acenter section 66. Each of these sections 62, 64 and 66 may have aD-shaped diameter (or other shaped diameter) to match the D-shapeddiameter of the valve 14 and the annuloplasty ring 12. The centersection 66 of the balloon 60 has a smaller diameter than the bulbsections 62 and 64. The first and second bulb sections 62 and 64 and thecenter section 66 may be inflated together or separately. Further, thesections 62, 64 and 66 may have multiple chambers to accommodatemultiple fluids (i.e., an inflation fluid and a cooling fluid).

To repair the mitral valve 14 with the apparatus 10 using a percutaneous(or intravascular) approach, the annuloplasty ring 12 is properly sizedfor the mitral valve by the surgical team using fluoroscopic and/orechocardiographic data. The annuloplasty ring 12 may be cooled using acryogenic source or other suitable means to place the support member 30in its first configuration. The annuloplasty ring 12 is then positionedabout the center section 66 of the balloon 60. It is contemplated thatthe annuloplasty ring 12 could alternatively, or as a supplement, becooled by infusing the balloon with a cooling fluid or other medium. Theconstraining wire 52 is pulled tight, which results in the wing members40 bending radially inward from their convex cross-sectional shape tothe flatter cross-sectional shape of FIG. 6. The delivery capsule 54 isthen placed over the balloon 60 and the annuloplasty ring 12. Inside thecapsule 54, the hook members 46 are bent upward in the proximaldirection B. The apparatus 10 is then loaded into an 16 to 22 Frenchcatheter (not shown) in a known manner.

The apparatus 10 is introduced into the right jugular vein using a knownpercutaneous technique called the Seldinger technique and is advancedthrough the superior vena cava to approach the right atrium. Thecatheter is then passed through the interatrial septum to reach the leftatrium. Inside the left atrium, the apparatus 10 is positioned justabove the mitral valve 14 as is shown in FIG. 6.

Next, the delivery capsule 54 is opened, which exposes the balloon 60and the annuloplasty ring 12 and also allows the hook members 46 tospring back to the position illustrated in FIG. 7. The balloon 60 isthen advanced distally into the annulus 15 of the mitral valve 14 untilthe center section 66 of the balloon 60 (where the annuloplasty ring 12is positioned) is at the level of the annulus, as shown in FIG. 8.

Next, the balloon 60 is inflated to radially expand the annuloplastyring 12 into full and complete engagement with the valve annulus 15.When the balloon 60 is inflating, the first bulb 62 pushes the valveleaflets 16 and 18 back to protect the leaflets during expansion of thesupport member 30. The constraining wire 52 is loosed slightly tocompensate for the growing diameter of the expanding balloon 60, but thewire is not completely released. This keeps the wing members 40 heldagainst the balloon 60 for the time being, and also keeps the hookmembers 46 pointed above the level of the valve annulus 15. The balloon60 is inflated to the point where the ring 12 is over-expanded in orderto ensure full and complete engagement with diseased/dilated annulus 15.As is illustrated in FIGS. 9 and 10, this full annular engagement of thedistal end portion 32 of the support member 30 ensures that theannuloplasty ring 12 seats against the inside of the valve annulus 15and forms a point of fixation for the annuloplasty ring.

The constraining wire 52 is then released, which allows the main bodyportion 36 and the wing members 40 of the support member 30 to springback to their convex shape as shown in FIG. 11. As the wing members 40bend radially outward, the hook members 46 swing downward in the distaldirection A and embed into the cardiac wall 70 and the valve annulus 15.The embedded hook members 46 thus extend distally from the wing members40 into the cardiac wall 70 to provide the primary point of fixation forthe annuloplasty ring 12. As shown in FIG. 12, the convex shape of thesupport member 30 conforms to the concave shape of the valve annulus 15and the annuloplasty ring 12 becomes clamped in the annulus between thedistal end portion 32 of the support member and the distally extendinghook members 46.

As shown in FIGS. 13 and 14, the balloon 60 is then deflated and movedout of the valve annulus 15. FIG. 14 also illustrates the final step inthe process whereby exposure of the support member 30 to bodytemperature over time raises the temperature above the transition range.It is contemplated that the temperature of the support member 30 couldalso be elevated by infusing the balloon 60 with warm saline. Raisingthe temperature of the support member 30 above the transition rangecauses the annuloplasty ring 12 to contract, which reduces the size ofthe opening of the valve annulus 15 to a predetermined size and shapedefined by the second configuration for the support member 30. It shouldbe noted that the constriction of the annuloplasty ring 12 to thepredetermined size reduces the posterior portion of the annulus 15 butmaintains the desired inter-trigonal distance X as another mechanism offixation.

The constriction of the annuloplasty ring 12 due to the shape memorymaterial of the support member 30 thus reestablishes the size of thevalve annulus 15 to normal. The flexibility of the support member 30allows the annuloplasty ring 12 to follow the native shape and contourof the valve annulus, yet provide structural support for the annuluswhich improves the coaptation of the native leaflets 16 and 18 andrestores normal valve function.

Before the balloon 60 and the constraining wire 52 are completelywithdrawn, the competency of the remodeled valve 14 can be tested byechocardiogram. If necessary, the annuloplasty ring 12 can bere-positioned by tightening the constraining wire 52 to pull the wingmembers 40 and the hook members 46 upward and out of the cardiac wall 70and the annulus 15, and then re-inflating the balloon 60 to re-acquirethe annuloplasty ring. If the echocardiogram shows the valve repair tobe successful, then the constraining wire 52 is pulled out of theapertures 44 in the hook members 46 and the rest of the apparatus 10,including the balloon 60, is removed from the atrial chamber.

The present invention thus allows for the annuloplasty ring 12 to bedelivered in a cardiac catheterization laboratory with a percutaneousapproach under local anesthesia using fluoroscopic as well asechocardiographic guidance, thereby avoiding general anesthesia andhighly invasive open heart surgery techniques. This approach offerstremendous advantages for high risk patients with severe valvularregurgitation. It should be understood, however, that the presentinvention contemplates various other approaches, including standard openheart surgeries as well as minimally invasive surgical techniques.Because the present invention omits stitching of the annuloplasty ring12 in the valve annulus 15, surgical time is reduced regardless ofwhether an open or percutaneous approach is used.

The technique for implanting the annuloplasty ring 12 in the tricuspidvalve follows the same steps described above for the mitral valve 14,except that all of the delivery and implantation steps for a tricuspidannuloplasty ring take place inside the right atrium and on a dilatednative tricuspid valve. The annuloplasty ring 12 disclosed herein iscapable of achieving an adjustable restriction in a deeper portion ofthe posterior leaflet segment and in a small portion of the adjacentanterior leaflet. The septal leaflet segment is not usually required tobe shortened, so the tricuspid valve annuloplasty ring improves leafletcoaptation and valve function by restriction of the anterior andposterior portions of the native valve tricuspid annulus.

From the above description of the invention, those skilled in the artwill perceive improvements, changes and modifications. For example, itis contemplated that, in addition to the balloon-based apparatusdisclosed herein, a mechanical-based apparatus could be used to deliverand deploy the annuloplasty ring described herein. Such improvements,changes and modifications within the skill of the art are intended to becovered by the appended claims.

Having described the invention, we claim:
 1. An annuloplasty ring forrepairing a cardiac valve, said annuloplasty ring comprising: anexpandable support member having oppositely disposed proximal and distalend portions and a main body portion between said end portions, saidproximal end portion of said support member comprising a plurality ofwing members that extend from said main body portion; and each of saidwing members including at least one hook member for embedding into acardiac wall and the annulus of the cardiac valve to secure saidannuloplasty ring in the annulus.
 2. The annuloplasty ring of claim 1wherein said hook members, when embedded into the cardiac wall and thevalve annulus, extend distally from said wing members.
 3. Theannuloplasty ring of claim 1 wherein said main body portion has aconcave cross-sectional shape for conforming to the convex shape of thevalve annulus.
 4. The annuloplasty ring of claim 3 wherein each of saidwing members has a concave cross-sectional shape for conforming to theconvex shape of the valve annulus.
 5. The annuloplasty ring of claim 4wherein said main body portion and said wing members are resilientlybendable from said concave cross-sectional shapes into flattercross-sectional shapes for delivery and placement of said annuloplastyring.
 6. The annuloplasty ring of claim 5 further comprising aconstraining wire for temporarily holding said wing members in saidflatter cross-sectional shape, said hook members extending generallyradially when said wing members are being held in said flattercross-sectional shape by said constraining wire.
 7. The annuloplastyring of claim 6 wherein said hook members are resiliently bendable toextend proximally inside a delivery capsule during delivery of saidannuloplasty ring into the valve annulus.
 8. The annuloplasty ring ofclaim 1 further comprising a layer of biocompatible material covering atleast a portion of said distal end portion and said main body portion ofsaid support member.
 9. The annuloplasty ring of claim 1 wherein saidsupport member is made from a shape memory material that is responsiveto changes in temperature above and below a predetermined temperaturetransition range, said support member having a first configuration whenthe temperature is below said predetermined temperature transitionrange, said support member having a second configuration when heatedabove said predetermined temperature transition range.
 10. Theannuloplasty ring of claim 9 wherein said support member is insertableinto the annulus of the cardiac valve in said first configuration and isthereafter heatable above said predetermined temperature transitionrange to change said support member into said second configuration,wherein movement of said support member into said second configurationcauses a reduction in size of the opening defined by the valve annulus.11. The annuloplasty ring of claim 1 wherein said support member isexpandable by an inflatable balloon so that said annuloplasty ringengages the annulus of the cardiac valve.
 12. An apparatus for repairinga cardiac valve, said apparatus comprising: an annuloplasty ringincluding an expandable support member having oppositely disposedproximal and distal end portions and a main body portion between saidend portions, said proximal end portion of said support membercomprising a plurality of wing members that extend from said main bodyportion; each of said wing members including at least one hook memberfor embedding into a cardiac wall and the valve annulus to secure saidannuloplasty ring in the annulus of the cardiac valve; and an inflatableballoon for expanding said support member so that said annuloplasty ringengages the annulus of the cardiac valve.
 13. The annuloplasty ring ofclaim 12 wherein said hook members, when embedded into the cardiac walland the valve annulus, extend distally from said wing members.
 14. Theapparatus of claim 12 wherein said main body portion has a concavecross-sectional shape for conforming to the convex shape of the valveannulus.
 15. The apparatus of claim 14 wherein each of said wing membershas a concave cross-sectional shape for conforming to the convex shapeof the valve annulus.
 16. The apparatus of claim 15 where said main bodyportion and said wing members are resiliently bendable from said concavecross-sectional shapes into flatter cross-sectional shapes for deliveryand placement of said annuloplasty ring.
 17. The apparatus of claim 16further comprising a constraining wire for temporarily holding said wingmembers in said flatter cross-sectional shape, said hook membersextending generally radially when said wing members are being held insaid flatter cross-sectional shape by said constraining wire.
 18. Theapparatus of claim 17 wherein said hook members are resiliently bendableto extend proximally inside a delivery capsule during delivery of saidannuloplasty ring into the valve annulus.
 19. The apparatus of claim 12further comprising a layer of biocompatible material covering at least aportion of said distal end portion and said main body portion of saidsupport member.
 20. The apparatus of claim 12 wherein said supportmember is made from a shape memory material that is responsive tochanges in temperature above and below a predetermined temperaturetransition range, said support member having a first configuration whenthe temperature is below said predetermined temperature transitionrange, said support member having a second configuration when heatedabove said predetermined temperature transition range.
 21. The apparatusof claim 20 wherein said support member is insertable into the annulusof the cardiac valve in said first configuration and is thereafterheatable above said predetermined temperature transition range to changesaid support member into said second configuration, wherein movement ofsaid support member into said second configuration causes a reduction insize of the opening defined by the valve annulus.
 22. The apparatus ofclaim 12 wherein said balloon has an hourglass shape defined by firstand second bulb sections connected by a center section having a smallerdiameter than said bulb sections, said annuloplasty ring beingpositioned about said center section.
 23. A method for repairing acardiac valve, said method comprising the steps of: providing anannuloplasty ring having an expandable support member; placing theannuloplasty ring around an inflatable balloon in a secured manner;inserting the balloon and annuloplasty ring into an atrial chamber;advancing the balloon until the annuloplasty ring is positioned withinthe annulus of the cardiac valve to be repaired; expanding the supportmember with the balloon so that the annuloplasty ring engages theannulus of the cardiac valve to secure the annuloplasty ring in theannulus; securing the annuloplasty ring in the valve annulus; collapsingthe balloon; and removing the balloon from the atrial chamber.
 24. Themethod of claim 23 wherein the balloon has an hourglass shape defined byfirst and second bulb sections connected by a center section having asmaller diameter than the bulb sections, said step of placing theannuloplasty ring around the balloon further comprising the step ofpositioning the annuloplasty ring about the center section.
 25. Themethod of claim 24 wherein said step of advancing the balloon until theannuloplasty ring is positioned within the valve annulus furtherincludes the step of positioning the first bulb section within theleaflets of the native valve so that when the balloon is inflated thefirst bulb pushes the valve leaflets back to protect the leaflets duringexpansion of the support member.
 26. The method of claim 23 wherein saidsupport member has oppositely disposed proximal and distal end portionsconnected by a main body portion that has a concave cross-sectionalshape, said step of expanding the support member with the balloon sothat the annuloplasty ring engages the annulus of the cardiac valveincludes the step of conforming the concave main body portion to theconvex shape of the valve annulus to help locate and secure theannuloplasty ring in the valve annulus.
 27. The method of claim 26wherein the proximal end portion of the support member comprises aplurality of wing members that extend from the main body portion, eachof the wing members including at least one resiliently bendable hookmember extending from each of the wing members, said method furtherincluding the step of embedding the hook members into a cardiac wall andthe valve annulus to further secure the annuloplasty ring in the valveannulus.
 28. The method of claim 27 wherein each of the wing members hasa concave cross-sectional shape for conforming to the convex shape ofthe valve annulus, said method further comprising the step of pullingthe wing members into a flatter cross-sectional shape with aconstraining wire for placement of the annuloplasty ring, the hookmembers extending generally radially when the wing members are beingheld by the constraining wire.
 29. The method of claim 28 furthercomprising the step of bending the hook members to extend proximallyinside a delivery capsule for delivery of the annuloplasty ring.
 30. Themethod of claim 28 further comprising the step of releasing theconstraining wire after said step of expanding the support member withthe balloon so that the wing members bend radially outward to positionthe hook members above the valve annulus for embedding into the cardiacwall and the valve annulus.
 31. The method of claim 30 wherein said stepof releasing the constraining wire causes the hook members to embed intothe cardiac wall in the distal direction.
 32. The method of claim 23wherein the support member is made from a shape memory material that isresponsive to changes in temperature above and below a predeterminedtemperature transition range, the support member having a firstconfiguration when the temperature is below the predeterminedtemperature transition range and a second configuration when heatedabove the predetermined temperature transition range, said methodfurther including the step of cooling the support member prior toinserting the annuloplasty ring into the annulus of the cardiac valve inorder to place the support in the first configuration.
 33. The method ofclaim 32 further comprising the step of heating the support member abovethe predetermined temperature transition range so that the supportmember changes into the second configuration.
 34. The method of claim 33wherein said step of heating the support member is done following saidstep of expanding the support member with the balloon, said step ofheating the support member contracts the annuloplasty ring and therebyrestricts the valve annulus to support the annulus and correct valvularinsufficiency.
 35. The method of claim 33 wherein said step of heatingis accomplished by exposing the support member to body temperature. 36.The method of claim 23 wherein said step of inserting the balloon andannuloplasty ring into the atrial chamber is done percutaneously via anintravascular catheter.